hi ram.. i can feel your situation here.. cos i have some friends who work in sql server and can't figure out why there's no such thing as an Identity column in oracle...

but coming to the point,

There's no such Thing as an Identity column in Oracle. The same functionality is obtained by Primary Keys as u would probably already know. You can specify one (or more) columns as your PK while creating your table. You can insert a new number in the PK column by either using seq_name.nextval or use a Pre-insert trigger.